Progress in male contraception is inhibited because of a basic lack of knowledge about the molecular details of the testis. The goal of this project is to define the transcriptome of the various cell types of the testis and to concentrate on the gene products that are unique to the testis. The project will involve the use of the Affymetrix GeneChip system and RNA from mice to define the transcriptome. We will determine the genes transcribed in brain, liver and testes and then by analysis we will determine which gene products are unique to the testis. The results will be confirmed on limited numbers of genes by PCR, Northern blots and in situ hybridization. Special emphasis will be placed on testis specific genes that involve signaling pathways and/or metabolic pathways that could be potential targets for contraceptive drugs in the future.